Kambli Priti, Ajbani Kanchan, Sadani Meeta, Nikam Chaitali, Shetty Anjali, Udwadia Zarir, Georghiou Sophia B, Rodwell Timothy C, Catanzaro Antonino, Rodrigues Camilla
Microbiology Section, Department of Laboratory Medicine, P.D. Hinduja National Hospital and Medical Research Center, Mumbai, India.
Pulmonology Section, Department of Medicine, P.D. Hinduja National Hospital and Medical Research Center, Mumbai, India.
Diagn Microbiol Infect Dis. 2015 May;82(1):49-53. doi: 10.1016/j.diagmicrobio.2015.01.009. Epub 2015 Jan 29.
This study correlates MICs of rifampicin (RIF) and isoniazid (INH) with GenoType MTBDRplus assay results for drug-resistant Mycobacterium tuberculosis (MTB) clinical isolates. MICs of RIF and INH were established for 84 and 90 isolates, respectively, testing 7 concentrations of each drug. Genotypic resistance to each drug was determined by GenoType MTBDRplus assay with 50 representative mutations confirmed by pyrosequencing, with mutations in the rpoB gene associated with RIF resistance and mutations in the katG and/or inhA genes associated with INH resistance. Based upon the correlation of MICs with specific genetic profiles, relative resistance levels were established for each isolate. Results indicate that MTB phenotypic resistance, currently based upon the testing of isolate susceptibility to a single drug concentration, may be more accurately profiled via quantitative MICs, and therefore, the correlation of molecular diagnostic results with specific MICs may allow for more optimal treatment of infections.
本研究将利福平（RIF）和异烟肼（INH）的最低抑菌浓度（MIC）与耐药结核分枝杆菌（MTB）临床分离株的GenoType MTBDRplus检测结果进行关联。分别对84株和90株分离株测定了RIF和INH的MIC，每种药物测试7种浓度。通过GenoType MTBDRplus检测确定每种药物的基因型耐药性，50个代表性突变经焦磷酸测序确认，rpoB基因中的突变与RIF耐药相关，katG和/或inhA基因中的突变与INH耐药相关。基于MIC与特定基因谱的相关性，为每个分离株确定相对耐药水平。结果表明，目前基于对单一药物浓度的分离株敏感性测试的MTB表型耐药性，通过定量MIC可能会得到更准确的分析，因此，分子诊断结果与特定MIC的相关性可能有助于对感染进行更优化的治疗。
